Tags Fish Guide

Giant Threadfin

Tags Fish Guide

Category: Medium Risk

GIANT threadfin are powerhouses. I had yearned to catch one for years and when I did, in a creek north of Karratha, it wasn’t a disappointment. Boy does that tail push them through the water. A big threadie, as they are commonly called, is as much a highlight for me as a good barramundi; but they can be fickle. Keen eyes and polarised glasses may eventually be rewarded with the sight of a large threadie cruising just below the surface, which elicits an anxious cast. Often these cruisers are hard to tempt but when you do, hang on for an explosive ride! On a recent trip to Broome just about every restaurant offered threadfin salmon on the menu – but unfortunately most was overcooked. It’s a shame really because the flesh of a threadfin is rated quite highly in the North-West. These fish, also known as golden or king salmon, are great recreational targets in the creeks and lower reaches of northern rivers.

The threadie is most easily distinguished from its smaller cousins by its pectoral fin, which is divided with the lower portion consisting of four free filaments. Larger fish also tend to have a yellow tinge with yellow pectoral, pelvic and anal fins.

The all-tackle, Game Fishing Association of Australia, record is 14.6 kilos taken in Broome and that’s a big threadie, with anything over a metre in length being a good fish. However they have been recorded at 32kg from the Gulf of Carpentaria and are estimated to be able to grow up to 40kg – and that’s one I would like to pop a lure at!

The normal distribution range of threadies starts around Dampier/Karratha and extends right up to the Northern Territory border and beyond. They live in tropical inshore waters, estuaries and the tidal reaches of rivers preferring the shallow, turbid, stirred water generated by our big northern tides. Some anglers even look for milky water colouration to find threadies. They are normally found feeding in shallow water. Threadies generally only form loose schools but larger fish are mostly found in twos and threes or on their own.

Breeding and migration
As with several of our northern species (including barramundi) threadies are protandrous hermaphrodites, which means that mature fish start off as males and then become females at around 95cm. Threadies are thought to breed from October through to March, with the peak occurring in December. The eggs are planktonic, which means they drift somewhere near the surface.

Recreational line fishing is unlikely to have much impact on threadfin populations but they are very vulnerable to netting because they spend considerable time in shallow water. The recent untimely reintroduction of recreational netting from Onslow to Derby will no doubt be a blow to threadfin numbers. I still can’t believe that such a ridiculous decision could be made, whatever the justification. Commercial netting is of concern in certain key areas.

Tackle and bait

For me a baitcaster and lure is the way to chase threadies, but bait anglers could use a medium spinning outfit baited with a fish fillet, prawn or live bait. Sporting anglers may fish as light as 6kg in relatively clear water but given the initial powerful runs you will experience with a decent threadie, perhaps 8-10kg is the way to go. My baitcaster is loaded with 15kg braid so I can stop a decent fish from burying me in snags.

Fishing methods
Without doubt, for me at least, the nicest way to chase big threadies is to sight cast lures for them, but that’s not always possible, or successful for that matter. Blind casting to small run-offs and colour changes in the water is more likely to result in a hookup. Boat anglers can troll for them but this should be done slowly as a strike from a decent threadie can be quite deceiving at times. It can feel far more like a snag than a strike as they take your lure slowly. Generally shallow running lures are best for casting around dropoffs and sandbanks. Lures such as Bombers (especially in gold), Scorpions (especially in fluoro colours), Rapala Husky Jerks and Nilsmaster Spearheads are all proven fish-takers. Trolling lures would include Halco Scorpions, Classic Lures and Tilsans. Slow, twitching retrieves seem to work best for me but every fish can have a different preference so just keep casting and keep varying it. Bait anglers can fish the same locations and wait for the fish as they move past on their way up or down the creek with the tide. A well-presented live bait can also give you a chance of a nice barra too.

References: Marine Fishes of Northern Australia by Gerry Allen and Roger Swainston. Australian Fisheries Resources by Kailola, Williams, Stewart, Reichelt, McNee and Grieve

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